Question

I have two tables in database:

comments table                  users table
| u_id | text |                 | u_id | premium |
|   9  |  ..  |                 |   9  |    1    |
|  10  |  ..  |                 |  10  |    0    |
|   9  |  ..  |

I want to select text from comments table for user in case only when this user has premium status (1). But if I want to check status of this user I need do another mysql query. Is this possible to do check that in one query?

$premium=sql_select("SELECT premium FROM users WHERE u_id LIKE '".$_GET['u_id']."'");

if ($premium[1][0]=1) {
$text=mysql_query("SELECT text FROM comments WHERE u_id LIKE '".$_GET['u_id']."'");
}
else //this user has no premium account so text will not be selected.

Answer 1

Use an (inner) join:

SELECT text
FROM comments_table c 
JOIN users_table u ON u.u_id = c.u_id AND u.premium = 1
WHERE c.u_id = ?